1. Field of the Invention
This invention relates to a video signal processing device and more particularly to a video signal processing device having a memory which is capable of temporarily storing a video signal.
2. Description of the Related Art
The art of processing a video signal by using a memory includes a process for suppressing noises by forming a video signal which is delayed by one field or one frame; and a special effect process for obtaining a wiping or fading effect between a video signal stored in the memory and a normal input video signal.
In the field of business video apparatuses, it has been practiced to give special composite or synthetic pictures by combining a plurality of video signals. Meanwhile, such special composite pictures have recently come to be desired also for a home video apparatus.
For example, special image effects attainable by the camera-integrated type VTR which has recently become popular can be further diversified with the wipe- or fade-effect attaining process combined with the above-stated composite image attaining process. Further, insertion of a border line in between picture components of a composite picture or insertion of a color back in a vacant part of an image would make a picture much clearer.
Further, while it is conceivable to singly appreciate an enlarged picture by using a memory, such a picture would become more interesting when combined with other pictures. Further, application of the wipe- or fade-effect process to such an enlarged picture in combination would further diversify the available special image effects.
In actuality, however, home video apparatuses are generally not arranged to be capable of performing the above-stated special processes, because:
The above-stated video signal processes and the circuit designs for them have been individually formed. An attempt to consolidate them would require use of a vary large number of memories and a highly complex circuit arrangement. In other words, in order to carry out every one of these processes, the VTR must be provided with many circuits including processing circuits for suppressing noises, for combining images and for obtaining the wiping and fading effects; a designation circuit for determining an image combining pattern in obtaining a composite image; a processing circuit for enlarging an image; and a circuit for inserting a border line in between pictures. As a result, circuits must be arranged on a very large scale.
Further, in a home VTR, these processes must be simply accomplished. However, they require complex instructions for designating an image combining pattern, a border line generating position, etc. Generally, it is too toilsome for home VTR operators to give such complex instructions.